U.S. patent number 5,662,591 [Application Number 08/451,173] was granted by the patent office on 1997-09-02 for apparatus for exercising and measuring strength of a patient's limb and an adjustable pivot clamp.
This patent grant is currently assigned to The Charlotte-Mecklenburg Hospital Authority, The Johns Hopkins University. Invention is credited to Ellen Jane MacKenzie, Melissa Lee McCarthy, Richard D. Peindl.
United States Patent |
5,662,591 |
Peindl , et al. |
September 2, 1997 |
**Please see images for:
( Certificate of Correction ) ** |
Apparatus for exercising and measuring strength of a patient's limb
and an adjustable pivot clamp
Abstract
An apparatus for measuring the strength of and for performing
physical therapy exercises to strengthen a patient's limb. The
device includes a pair of pivot clamps each having a end for
connecting the pivot clamps to a solid object such as a physical
therapy table or hospital bed. A second end of each pivot clamp
adjustably receives a first frame member of a conventional traction
or load frame. This arrangement enables rotational and
translational movement of the first frame member retained by the
pivot clamp relative to each pivot clamp to allow the frame to be
positioned in a desired location and orientation relative to the
patient's limb to be tested. A second frame member is adjustably
connected to the pair of first frame members by a pair of
adjustable brackets. A limb engaging member having a force
transducer located therein is used to both engage the patient's
limb to be tested and to detect a force transmitted between the
limb of a patient and the limb engaging member. The force
transducer produces an output which is representative of the force
produced which may be displayed on a digital panel meter.
Inventors: |
Peindl; Richard D. (Charlotte,
NC), McCarthy; Melissa Lee (Baltimore, MD), MacKenzie;
Ellen Jane (Baltimore, MD) |
Assignee: |
The Johns Hopkins University
(Baltimore, MD)
The Charlotte-Mecklenburg Hospital Authority (Charlotte,
NC)
|
Family
ID: |
23791097 |
Appl.
No.: |
08/451,173 |
Filed: |
May 26, 1995 |
Current U.S.
Class: |
601/24; 5/648;
601/33; 73/379.01 |
Current CPC
Class: |
A61B
5/224 (20130101); A63B 23/0494 (20130101); A63B
2220/51 (20130101) |
Current International
Class: |
A61B
5/22 (20060101); A63B 23/04 (20060101); A63B
24/00 (20060101); A61B 005/103 () |
Field of
Search: |
;128/774
;601/23,24,33-35 ;73/379.01 ;482/137,142,909
;248/222.52,286.1,287.1,298.1 ;5/601,621,623,624,646,648 |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Knee Extension Torque in Stroke Patients: Comparison of
Measurements Obtained With a Hand-Held and a Cybex Dynamometer, R.
W. Bohannon, Physiotherapy Canada, Nov./Dec., vol. 42, No. 6, pp.
284-287. .
A Static Dynamometer Measuring Multidirectional Torques Exerted
Simultaneously at the Hip and Knee, D. Bourbonnais et al., J.
Biomechanics, vol. 26, No. 3, pp. 277-283, 1993..
|
Primary Examiner: Clark; Jeanne M.
Attorney, Agent or Firm: Bell, Seltzer, Park & Gibson,
P.A.
Claims
That which is claimed:
1. An apparatus adapted for use in exercising and measuring
strength of a patient's leg, said apparatus comprising:
a slide rail;
a frame member;
a pivot clamp having a first plate defining an opening in a first
end, said first end also including a clamping mechanism for
connecting the first plate in a desired location and orientation to
said slide rail and said pivot clamp having a second plate
connected to said first plate and selectively rotatable relative
thereto, said second plate having a second end for connecting said
frame member in a desired location and orientation relative to the
patient's limb, wherein said pivot clamp provides selected
rotational and translational movement between said slide rail and
said frame member;
a limb engaging member connected to said frame member and movable
therewith and adapted for engaging the patient's limb; and
a force transducer connected to said limb engaging member for
detecting a force transmitted between said limb engaging member and
the patient's limb, said force transducer producing an output
representative of the detected force.
2. An apparatus according to claim 1 wherein said second plate is
in releasable frictional engagement with said first plate.
3. An apparatus according to claim 2 further comprising locking
means for locking said second plate relative to said first plate
when said second plate is in the desired location.
4. An apparatus according to claim 3 wherein said locking means
comprises a threaded shaft extending outward from said first plate
and tightening means threadingly cooperating therewith for locking
said second plate to said first plate in the desired position.
5. An apparatus according to claim 2 further comprising locating
means for rotationally locating said second plate relative to said
first plate.
6. An apparatus according to claim 5 wherein said locating means
comprises a plurality of spaced first apertures located in said
first plate and a plurality of spaced second apertures located in
said second plate so as to selectively align with said first
apertures, and a release pin insertable in one of said first
apertures and one of said second apertures to position said second
plate relative to said first plate.
7. An apparatus according to claim 6 wherein said release pin is
connected to said second plate.
8. An apparatus according to claim 7 wherein said plurality of
second apertures are fewer in number than said plurality of first
apertures.
9. An apparatus according to claim 1 wherein said pivot clamp
further comprises a first adjustable bracket attached to said
second end to enable said frame member rotational and translational
movement relative said pivot clamp to thereby enhance the
positioning and orientation of said frame member relative to the
patient.
10. An apparatus according to claim 1 further comprising a second
adjustable bracket for adjustably connecting a second frame member
to said frame member, such that said second frame member is
oriented generally transverse to said frame member, and enabling
said second frame member translational and rotational movement
relative to said frame member for positioning said limb engaging
member in a desired location and orientation relative to the limb
to be measured.
11. An apparatus according to claim 1 wherein said force transducer
comprises:
a housing;
a bracket attached to said housing for connecting said housing to
said frame member for positioning said housing in the desired
location; and
a strain gauge connected to said housing and oriented to cooperate
with said limb engaging member.
12. The apparatus according to claim 11 wherein said limb engaging
member comprises a mounting member pivotally connected to said
housing and a retaining strap adapted for releasably attaching to
and retaining the patient's limb.
13. An apparatus according to claim 11 wherein said force
transducer selectively measures both compression and tensile force
applied to said engaging means.
14. An apparatus according to claim 1 further comprising a display
for displaying said output.
15. An apparatus according to claim 14 wherein said display
comprises means for converting said output received from said force
transducer to a digital representation.
16. An apparatus according to claim 1 wherein said frame member
comprises indexing means located along a surface thereof enabling
said limb engaging member to be repeatedly positioned in the
desired location relative to said pivot clamp and the patient's
limb.
17. An apparatus according to claim 1 wherein said pivot clamp
includes indexing means located along a surface thereof enabling
said pivot clamp and said frame member to be repeatedly positioned
relative to the patient's limb.
18. An apparatus adapted for use with a table and a load frame
having a pair of first opposed frame members and a second frame
member attached generally transverse to the pair of first frame
members, said apparatus comprising:
a pair of slide rails adapted to be connected to the table;
a pair of pivot clamps, each of said pair of pivot clamps having a
first plate defining an opening in a first end, each said first end
also including a clamping mechanism for connecting each said first
plate in a desired location and orientation to a respective one of
said pair of slide rails, and each of said pair of pivot clamps
having a second plate rotatably connected about a generally
horizontal axis to said first plate, said second plate having a
first adjustable bracket attached at a second end thereof adapted
for connecting said first opposed frame members in a desired
location relative to the patient's limb, wherein said pair of pivot
clamps each provides selected rotational and translational movement
between the table and said first opposed frame members;
a limb engaging member adapted to be connected to the load frame
and movable therewith for engaging the patient's limb in the
desired location; and
a force transducer connected to said limb engaging member for
detecting a force transmitted between said limb engaging member and
the patient's limb, said force transducer producing an output
representative of the force detected between the patient's limb and
said limb engaging member.
19. An apparatus according to claim 18 wherein each of said pivot
clamps further comprises:
locating means for locating said second plate relative to said
first plate; and
locking means for locking said second plate relative to said first
plate when said second plate is positioned in the desired
location.
20. An apparatus according to claim 18 wherein said force
transducer comprises:
a housing defining a cavity;
a third adjustable bracket for connecting said housing to the load
frame for positioning said housing in the desired location; and
a strain gauge received within said cavity and oriented so as to
cooperate with said limb engaging member.
21. The apparatus as defined in claim 20 wherein said limb engaging
member comprises a mounting member pivotally connected to said
housing and a retaining strap adapted for attaching to and
retaining the patient's limb to be measured.
22. An apparatus according to claim 20 wherein said force
transducer selectively measures both compression and tensile
strength applied to said engaging means.
23. An apparatus according to claim 18 further comprising a digital
panel meter for displaying said output received from said force
transducer in digital form.
24. A pivot clamp for use with a rigid frame and a physical therapy
table, said pivot clamp comprising
a body portion having a first end, said first end also including a
clamping mechanism for providing said pivot clamp rotational and
translational movement relative to the physical therapy table;
a first plate connected to said body portion generally transverse
to a longitudinal axis thereof, said first plate having
substantially smooth opposed faces;
a second plate connected for rotational movement with respect to
said first plate and having a substantially smooth face in
releasable frictional engagement with said first plate;
locating means for rotationally locating said second plate relative
to said first plate;
locking means for locking said second plate relative to said first
plate when said second plate is positioned in the desired location;
and
a first adjustable bracket connected to said second plate and
movable therewith and adapted for receiving the rigid frame to
allow translational and rotational movement relative to said
adjustable bracket, and said first adjustable bracket enabling said
second plate and the rigid frame received therein to pivot relative
to the table and said first plate so as to position the rigid frame
in a desired location and orientation.
25. An apparatus according to claim 24 wherein said locking means
comprises a threaded shaft extending outward from said first plate
and tightening means threadingly cooperating therewith for locking
said second plate to said first plate in the desired position.
26. An apparatus according to claim 24 wherein said locating means
comprises a plurality of spaced first apertures located in said
first plate and a plurality of spaced second apertures located in
said second plate so as to selectively align with said first
apertures, and a release pin insertable in one of said first
apertures and one of said second apertures to position said second
plate relative to said first plate.
27. An apparatus according to claim 26 wherein said release pin is
connected to said second plate.
28. An apparatus according to claim 27 wherein said plurality of
second apertures are fewer in number than said plurality of first
apertures.
29. An apparatus according to claim 24 wherein said first plate
includes indexing means located along a surface thereof to allow
said second plate to be repeatedly positioned relative thereto.
30. An apparatus according to claim 24 wherein said first plate has
a generally circular configuration.
31. An apparatus according to claim 24 wherein said second plate
has a generally rectangular configuration with a pair of curved
opposed ends which correspond in shape to said first plate.
32. An apparatus according to claim 24 wherein said body portion
and said first plate comprise a unitary one-piece structure.
Description
FIELD OF THE INVENTION
The present invention relates to the field of muscle physical
therapy and strength measuring devices, and, more particularly, to
an apparatus and method for measuring the strength of and for
performing physical therapy exercises to strengthen a patient's
limb.
BACKGROUND OF THE INVENTION
It has long been recognized as beneficial to patient recovery that
exercise or physical therapy begin as soon as possible after an
operation to replace or repair an injured joint or limb. It has
traditionally been popular to use a conventional orthopedic
traction frame similar to that disclosed in U.S. Pat. No. 4,551,872
to Reed to assist a patient in performing remedial exercises. For
example, U.S. Pat. No. 3,612,042 to Fry uses a fixed traction frame
and adds a number of attachments, such as a swivel assembly and a
series of members, to allow a patient to passively exercise his hip
while remaining in the hospital bed.
Similarly, U.S. Pat. No. 4,602,618 to Berze discloses the use of a
continuous hip-joint motion machine which is attached to a hospital
bed. The machine also uses a fixed traction frame to support a
series of pulleys which cooperate with the machine to passively
exercise the hip joint after replacement surgery.
U.S. Pat. No. 2,855,199 to Noland et al., discloses a progressive
resistance device which is removably mounted to a table for
exercising both the hamstring and quadriceps femoris muscle
groups.
In addition to exercising or rehabilitating injured joints or
limbs, it is also important for physicians, physical therapists and
exercise physiologists to be able to quantitatively measure and
test the strength of a patient's joint or limb prior to, and as a
result of exercise and/or surgery. Typically, such testing methods
include the use of hand-held dynamometers. For instance, an article
by Bohannn entitled Knee Extension Torque In Stroke Patients:
Comparison of Measurements Obtained With A Hand-Held Dynamometer
("HHD") And A Cybex Dynamometer discloses the difficulty a tester
has in holding a HHD steady during testing of knee extension, if
the patient comes to maximal force immediately. In addition, the
article discloses the importance of the tester's strength and skill
in obtaining accurate measurements.
Rather than using a hand-held dynamometer, complicated devices such
as U.S. Pat. No. 5,078,152 to Bond et al. have been developed. The
Bond et al. patent discloses a method for diagnosis and/or training
of proprioceptor feedback in a muscle and joint system of a human
patient. The device is a stand alone unit which includes a passive
exercise resistance system having a force measuring system and a
position measuring system to determine exercise parameters and feed
signals to a computer control system which runs a software program
to control the exercise to be performed by a patient. Similarly,
U.S. Pat. No. 3,374,675 to Keropian discloses an isometric muscle
testing apparatus which requires a slide-block to attach a
complicated arrangement of a support bar, a tubular channel support
member, a positioning bar, a lockable hinge brake, a measuring arm,
a split sleeve, and a load cell assembly to a table. This
arrangement is unstable and subject to inaccurate results because
of the inherent flexing of the apparatus and the torsional force
applied to the load cell assembly during testing, due to the number
of interconnected bars and rods secured to the table by the
slide-block.
Load or traction frames currently available are limited in their
ability to be adjusted to accommodate exercise equipment.
Specifically, existing traction frames do not possess the structure
necessary to allow it to be pivoted about a horizontal axis
relative to the hospital bed or physical therapy table. As a
result, there are only a finite number of adjustments which can be
made to position the traction frame and the associated exercise
equipment relative to the patient. Consequently, patients are
unable to take full advantage of the benefits of exercise while
recovering in a hospital bed.
The ability to test limb strength of a patient is an important
indicator of a variety of factors, such as pre-operation versus
post-operation strength. It is therefore desirable to obtain the
most reliable quantitative results possible. Existing testing
methods use either hand-held dynamometers, which are heavily
dependant on the strength and ability of the tester or a machine
such as a Cybex dynamometer, requiring a patient to be moved from a
hospital bed for testing. In addition, such machines compete for
limited hospital budgets because of their associated cost.
Consequently, hospitals are faced with a choice between using
expensive equipment to conduct their tests of patients or rely on a
hand dynamometer which makes quantifiable results in repeated tests
difficult to achieve.
SUMMARY OF THE INVENTION
In view of the foregoing background, it is therefore an object of
the invention to provide an apparatus and an associated method for
measuring the strength of and rehabilitating a patient's limb.
These and other objects, features, and advantages of the invention
are provided by a pair of pivot clamps each having a first end for
connecting each of the pivot clamps to a solid object such as a
physical therapy table or hospital bed. A second end of each pivot
clamp adjustably receives a first frame member of a conventional
traction or load frame. The load frame also includes a second frame
member which spans the distance between and is connected to the
pair of first frame members by a pair of adjustable brackets. Such
an arrangement enables the load frame retained by the pivot clamps
to move longitudinally and rotate relative to each pivot clamp to
allow the load frame to be positioned in a desired location
relative to the patient's limb.
The pair of first frame members and the second frame number
cooperate with the pair of pivot clamps to provide a rigid
structure or frame which partially surrounds the physical therapy
table or the hospital bed to enable the rigid frame to be
positioned in a plurality of locations relative to the patient's
limb. Alternatively, rather than provide a rigid frame, it is
possible to use only one pivot clamp, which retains one first frame
member and an adjustable bracket to adjustably connect a second
frame member to the first frame member such that the second frame
member is oriented generally traverse to the first frame member.
Preferably, the second frame member is slidably and rotatably
adjustable relative to the first frame member to position the limb
engagement means in a desired location relative to the limb to be
measured.
It is also beneficial to provide a limb engaging member which can
be adjustably connected to at least one of the frame members and be
movable therewith to engage the patient's limb in the desired
location during measurement thereof. A force transducer is
preferably connected to the limb engaging member to detect a force
transmitted between the limb engaging member and the limb of the
patient. The force transducer preferably produces an output which
is representative of the force produced between the patient's limb
and the limb engaging member. This representative output is capable
of being displayed on a display means such as a digital panel
meter.
It is advantageous for the force transducer to include a housing
which defines a cavity for receiving therein a strain gauge which
cooperates with the limb engaging member. The limb engaging member
preferably includes a retaining strap which releasably attaches to
and securely retains the patient's limb to be measured in such a
manner that it allows for measuring of both compression and tensile
strength of the patient's limb.
To enhance the ability to position the limb engaging member
relative to the patient, it is beneficial for a slide rail to be
attached to one or both sides of the physical therapy table. In
connection therewith, a first end of the pivot clamp preferably
includes an adjustable bracket which enables translational movement
of the pivot clamp relative to the slide rail for positioning the
pivot clamp and the frame member along a horizontal path relative
to the patient positioned on the physical therapy table. This
configuration also allows for rotational movement of the pivot
clamp and the frame member about the longitudinal axis of the slide
rail relative to the patient and the table.
In addition, indexing means is preferably provided on both the
pivot clamp, the frame members, and when used, the slide rail to
allow the patient's limb, the rigid frame, and the limb engaging
member to be readily positioned in the same location on subsequent
tests.
An alternative use of the apparatus is for purposes of exercising
and rehabilitating a patient's limb. As previously described, the
rigid frame is formed from a pair of first frame members adjustably
attached by a pair of brackets to a second frame member, enabling
each of the frame members to move relative one another. Both
translational and rotational movement of the frame members is
possible.
The rigid frame is secured by a pair of pivot clamps to the
physical therapy table or the like. The pivot clamps enable each of
the pair of first frame members received therein, to pivot relative
to the physical therapy table and undergo translational and
rotational movement relative to each of the pivot clamps so as to
enable the rigid frame to be positioned in the desired location and
orientation relative to the patient.
In addition, as with the testing apparatus previously described, it
is beneficial to provide a pair of slide rails along the
longitudinal edges of the physical therapy table to enable
rotational and translational movement of the rigid frame relative
to the patient, thereby enhancing the ability to position the rigid
frame in the desired location.
A plurality of exercise apparatuses are preferably adapted to be
received on the rigid frame to enable the patient to exercise and
rehabilitate the desired body part. In addition, it is possible to
attach more than one rigid frame to the physical therapy table in
order that the two rigid frames may cooperate to receive a more
complicated exercise apparatus for exercising and rehabilitating
the desired body part. The ability of the rigid frame and the pivot
clamp to undergo pivotal, translational and rotational movement
relative to each other and relative to the hospital bed or physical
therapy table allows infinite variability of the device.
BRIEF DESCRIPTION OF THE DRAWINGS
Some of the objects and advantages of the present invention have
been stated, others will appear as the description proceeds, when
taken in conjunction with the accompanying drawings in which;
FIG. 1 is a side view in perspective of the apparatus during
performance of an isokinetic assessment of a patient's limb in
accordance with the present invention;
FIG. 2 is a side view in perspective, partially in phantom, of the
pivot clamp shown in FIG. 1;
FIG. 3 is an exploded view of the pivot clamp shown in FIG. 2;
FIG. 4 is an end view of the pivot clamp shown in FIGS. 2 and
3;
FIG. 5 is a side view in perspective of the limb engagement means
shown in FIG. 1;
FIG. 6 is a side view in cross-section taken along line 6--6 of
FIG. 5;
FIG. 7 is a side view in perspective of the apparatus during the
performance of physical therapy in accordance with the present
invention; and
FIG. 8 is a perspective view of the limb engagement means showing
the retaining strap securing a patient's limb during the
performance of a isokinetic assessment of the limb in accordance
with the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention now will be described more fully hereinafter
with reference to the accompanying drawings, in which preferred
embodiments of the invention are shown. This invention may,
however, be embodied in many different forms and should not be
construed as limited to the embodiments set forth herein; rather,
these embodiments are provided so that this disclosure will be
thorough and complete, and will fully convey the scope of the
invention to those skilled in the art. Like numbers refer to like
elements throughout.
In the embodiment shown in FIGS. 1-6 and 8, the device includes a
pair of pivot clamps 10 which are capable of being attached to
either a physical therapy table or the like, generally designated
as AA, or to a solid object such as a wall, door or the like (not
shown). The pivot clamps 10 each cooperate with a plurality of
frame members 12a-12c to form a rigid frame, generally designated
as 14. In this embodiment, the frame members 12a-12c are
conventional load or traction frame components which are readily
available at most hospitals and physical therapy centers. A limb
engaging member 16 releasably connects at one end thereof to the
rigid frame 14 and at its opposite end to a patient's limb to be
measured. A force transducer, generally designated at 18, is
connected to the limb engaging member 16 for detecting a force
transmitted between the patient's limb and the limb engaging
member.
As shown in detail in FIGS. 2-4, each of the pivot clamps 10
includes a body portion 20 having a first end 22 which, in the
embodiment shown, defines a first key-hole shaped opening 24
adapted to receive a slide bar 26 fastened to the physical therapy
table AA. It is to be understood however that first end 22 may be a
mounting plate (not shown) to fixedly attach each of the pivot
clamps 10 to the physical therapy table AA or a fixed object such
as a wall.
A second opening 28 in the body 20 is oriented generally transverse
to the first opening 24 for threadingly receiving an adjustable
retaining screw 30. The retaining screw 30, when loosened,
selectively allows both translational and rotational movement of
each pivot clamp 10 on the slide rail 26 in the direction of arrows
BB and CC, respectively, as shown in FIG. 2, to the desired
position and orientation relative to the patient located on the
physical therapy table AA. The retaining screw 30 is then tightened
to secure the pivot clamp 10 into position.
A first plate 32 is integrally formed with the body portion 20. The
first plate 32 has a generally circular configuration with a
substantially smooth front face 31 and peripheral edge 33 and is
oriented generally transverse to the longitudinal axis of the body
portion 20. A plurality of first apertures 34 are located along the
peripheral edge 33 of the front face 31 of the first face plate 32.
The plurality of first apertures 34 are spaced apart in ten degree
intervals around the entire first face plate 32. It is to be
understood however that the intervals between the plurality of
first apertures 34 may vary as desired. Centrally located in the
first face plate 32 and extending generally transverse thereto, is
a shaft 36 having a threaded free-end 37.
A second end of the pivot clamp 10 comprises a second face plate 38
having a substantially smooth front face 39. The second face plate
38 includes a mounting collar 40. The mounting collar 40 defines a
bore 42 sized to receive the shaft 36. The collar 40 is adapted to
be seated on the shaft 36 enabling the threaded free end 37 of the
shaft to project outward therefrom. The second face place 38 has a
generally rectangular configuration with a pair of opposed
substantially smooth curved peripheral ends 41 which correspond in
shape and size to the peripheral edge 33 of the first face plate
32. A plurality of second apertures 48 are located along the curved
peripheral edge of the second face plate 38. The second apertures
48 may be spaced at a distance similar to that of the first
apertures 34. Alternatively, it is possible to space the second
apertures 48 a distance which is either greater or less than that
of the first apertures 34.
After the second face plate 38 is seated on the shaft adjacent the
first face plate 32, a washer 44 is fitted onto the threaded
free-end 37 of the shaft 36. A tightening means, which in this
embodiment is a wing nut handle 46 having an internal threaded bore
47 is then threaded onto the shaft 36 so as to selectively lock the
second face plate 38 relative to the first face plate 32, once the
second face plate 38 has been rotated to the desired position. It
is to be understood that a wide variety of tightening means may be
used, such as a nut or other conventional fastener and remain
within the spirit of the invention.
A release pin, in this embodiment a quick release pin generally
indicated at 50, is secured to the front face 39 of the second face
plate 38 such that a pin portion 52 is received in a mounting
aperture 53. The handle 54 of the quick release pin 50 is movable
between a first position (shown in phantom in FIG. 2) and a second
position (shown in FIG. 4). In the first position, the handle 54 is
in general longitudinal alignment with the pin portion 52, which
causes the pin portion to be retracted toward the handle so that
the pin portion does not project beyond the second face plate 38.
The retraction of the pin portion 52 from the first apertures 34
enables pivotal movement of the second face plate 38 relative to
the first face plate 32 in the direction of arrow DD as shown in
FIGS. 2, 4, and 7.
To allow the second face plate 38 to pivot in the first position,
it is also necessary for the wing nut handle 46 to be loosened
about the shaft 36. When the second face plate 38 has been pivoted
to the desired position relative to the first face plate 32, the
mounting aperture 53 aligns with one of the plurality of first
apertures 34. The handle 54 of the quick release pin 50 is then
moved to the second position wherein the pin portion 52 projects or
is inserted into the aligned first aperture 34 of the first face
plate 32. The wing nut handle 46 is then tightened in a generally
clockwise direction to lock the second face plate 38 relative to
the first face plate 32. The second apertures 48 are located on
either side of the mounting aperture 53 to assist in aligning the
mounting aperture with one of the first apertures 34.
The front face 39 of the second face plate 38 also has a first
adjustable bracket 56 secured thereto by conventional means such as
a screw 57. The first adjustable bracket 56 is adjustable by means
of a bracket handle 58 which alternatively loosens and tightens the
adjustable bracket so as to receive one of the first frame members
12a or 12b. As shown in FIGS. 2 and 4, the first adjustable bracket
56 is adapted to receive the first frame member 12b. In this
embodiment, the rigid frame 14 is formed from frame members 12a-12c
having a generally octagonal cross-section which enables both
rotational movement about the longitudinal axis of the respective
first frame members 12a and 12b in the direction of arrow EE and
translational movement of the respective frame members relative to
the pivot clamp 10 in the direction of arrow FF shown in FIGS. 2
and 4 when the first adjustable bracket 56 is loose.
Based upon the ability of the second face plate 38 to also pivot
relative to the first face plate 32 in the direction of arrow DD,
the rigid frame 14 may be pivoted horizontally relative to the
physical therapy table AA. The second frame member 12c is also
adjustably attached to the first frame members 12a and 12b by a
pair of second adjustable brackets 59a and 59b. The second
adjustable brackets 59a, 59b allow translational movement of the
second frame member 12c relative to the pair of first frame members
12a, 12b in the direction of arrow GG to move it closer or further
from the table AA and rotational movement of the second frame
member about its longitudinal axis in the direction of arrow HH in
FIG. 1. Accordingly, the rigid frame 14 may be infinitely adjusted
about any or all of the described three degrees freedom in order to
position the limb engaging member 16 in the desired location and
orientation relative to the patient's limb to be measured.
As shown in FIGS. 5, 6, and 8, the force transducer 18 includes a
housing 60 having a generally cylindrical configuration. The
housing 60 defines an internal cavity 62 for receiving therein a
strain gauge 64 oriented so as to cooperate with the limb engaging
member 16. The housing 60 of the force transducer 18 is connected
at one end thereof to a third adjustable bracket 66 having a
configuration similar to the first and second adjustable brackets
56 and 59a, 59b. A third adjustable bracket handle 68 enables the
force transducer 18 to be connected to one of the first pair of
frame members 12a and 12b or the second frame member 12c as well as
enable rotational movement relative to the longitudinal axis of the
respective frame member in this instance 12c in the direction of
arrow JJ in FIGS. 5 and 6 and allow translational movement relative
to the third adjustable bracket in the direction of arrow KK in
FIG. 5.
The limb engaging member 16 is pivotally connected to the housing
60 by means of a mounting member 70. The mounting member 70, as
shown in FIGS. 5 and 8, is a generally rectangular plate having
guides 72 located at opposed ends thereof for receiving a retaining
strap 74. In this embodiment, the retaining strap has a buckle and
loop arrangement which allows the retaining step 74 to be
releasably secured around a patient's leg to ensure that there is
no play between the limb engaging member 16 and the patient's leg.
It is to be understood that alternative forms of the retaining
strap 74 may be used as long as the retaining strap 74 easily opens
and closes to alternatively release and secure a patient's leg and
secondly has a fastening device which is sufficiently secure to
retain the patient's leg to avoid any excessive movement between
the patient's limb and the limb engaging member.
As may be seen in FIGS. 5, 6, and 8, the strain gauge 64 is
oriented along the longitudinal axis of the housing 60. The strain
gauge 64 is threadingly secured at one end thereof by a threaded
bolt 73 extending outward therefrom, to the second adjustable
bracket 66. The opposed end of the strain gauge 64 is secured by a
threaded nut and bolt, collectively referred to as 75, which allows
pivotal movement of the mounting member 70 relative to the housing
60 in direction LL as shown in FIG. 5. This arrangement also
enables the strain gauge 64 to form a solid attachment between the
frame member, in this embodiment, second frame member 12c, and the
mounting member 70 of the limb engaging member 16, to ensure that
any tensile or compression force exerted by the patient's limb is
directly transferred to the strain gauge. The strain gauge 64 of
the force transducer 18 produces an output which is representative
of the directed force applied by the patient's limb and transfers
this output to a display 76. A digital panel meter may be used for
displaying the output received from the force transducer 18 in
digital form.
The operation of the device will now be disclosed to better enhance
the understanding of the present invention. A patient is positioned
on the physical therapy table AA in a desired location, in this
instance, sitting on the edge of the table with both legs hanging
over the edge thereof. The rigid frame 14 is then moved from a
storage position (not shown). The retaining screw 30 of each of the
pair of pivot clamps 10 is loosened to enable translational
movement BB of each of the pivot clamps along the slide rail 26
toward the end of the table AA adjacent the patient. Once the pivot
clamps 10 have been moved adjacent the patient, in the desired
location, the retaining screw 30 of each of the pivot clamps is
tightened to prevent further sliding of the pivot clamps. The
handle 54 of the quick release pin 50 is then moved to the first
position retracting pin portion 54 from the aligned first aperture
34 of the first face plate 32 and the wing nut handle 46 is then
rotated in a counterclockwise direction to loosen the handle
relative to the shaft 36 of the first face plate 32.
The second face plate 38 of each pivot clamp, taking the rigid
frame 14 with it, is then pivoted downward in the direction of
arrow DD to the desired location, in this instance adjacent the
floor, as shown in FIG. 1. Once in the desired location, the handle
54 of the quick release pin 50 is moved to the second position
causing the pin portion 52 to project passed the second face plate
38 and into the aligned aperture 34. The wing nut handle 46 is then
rotated in the clockwise direction to tighten down the second face
plate 38 relative to the first face plate 34. If necessary, the
handle 58 of the first adjustable bracket 56 is loosened to allow
the first frame members 12a and 12b to translate longitudinally in
the direction of arrow FF relative to the pivot clamp 10 and move
second frame member 12c either closer to or further from the
patient seated upon the physical therapy table AA. The handle 58 is
rotated in a clockwise direction to tighten the adjustable bracket
56 about the first frame members 12a and 12b once the desired
location has been achieved. It is to be understood that adjustments
about all the available degrees of freedom need not be made to
position the rigid frame 14 in the desired position and orientation
for each test. However, the ability to move the rigid frame and
pivot clamps in such a multitude of degrees of freedom relative to
the patient and the table greatly enhances the versatility of the
device.
The limb engaging member 18 is then positioned laterally, i.e.,
undergoes translational movement, in the direction of arrow KK
relative to and/or rotated about the second frame member 12c in the
direction of arrow JJ by loosening the third adjustable bracket 66.
The force transducer 18 and the limb engaging member 16 should be
positioned so as to properly align with the limb of the patient to
be measured. The retaining strap 74 of the limb engaging member 16
is then comfortably secured about the patient's limb to be
measured.
Upon direction from the individual conducting the test, the patient
either flexes or extends the limb to exert either a compression or
tensile force, respectively against the limb engaging member 16.
The pressure exerted by the patient against the limb engaging
member 16 is transferred to the force transducer 18. The measured
force exerted by the patient is carried by a cable 80 to the output
display device 76 where it is displayed in a desired form, in this
case as a digital readout.
Each of the pair of first frame members 12a, 12b, the second frame
member 12c, the first face plate 32 and, when used, the slide rail
26 have index markings 82 along a surface thereof to enable the
pivot clamp 10, the limb engaging member 16, and the rigid frame 14
to be easily repeatably positioned in the same location for
subsequent tests to ensure uniformity and reliability of such
tests.
An alternative embodiment of the device is shown in FIG. 7. In this
embodiment, the device is intended for use in exercising or
conducting physical therapy of a patient's joint or limb. It is
anticipated, that the device will be used with a patient on a
physical therapy table or hospital bed designated AA'.
In this alternative embodiment, the pivot clamps 10' are used with
a rigid frame 14' similar to the one previously described. A
variety of exercise equipment may be attached to the rigid frame by
use of attachment means such as the third adjustable bracket
described above. In addition, a second rigid frame 14" may be used
in conjunction with the first rigid frame 14' to cooperatively
receive a variety of exercise equipment such as the weight and
sling shown generally at 78. It is to be understood that the rigid
frame 14' and the pivot clamps 10' are identical to those
previously discussed in the context of the preferred embodiment
shown in FIGS. 1-6 and 8. The ability of the pivot clamps 10' and
the rigid frames 14' and 14" to selectively move about the numerous
of degrees of freedom allows the rigid frame 14' to be adjusted in
an infinite variety of positions with a wide variety of exercise
equipment. For example, rather than using the pair of first frame
members 12a and 12b, and the second frame member 12c to form a
generally rectangular rigid frame 14, it is possible, within the
spirit of this invention, to use only the two first frame members
and an adjustable bracket such as second adjustable bracket 59a,
and rotate the pivot clamps 10 about the slide rails 26 in the
direction of arrow CC to create a triangular load frame (not shown)
or a variety of other configurations.
In the drawings and specification, there have been disclosed
typical preferred embodiments of the invention and, although
specific terms are employed, they are used in a generic and
descriptive sense only and not for purposes of limitation, the
scope of the invention being set forth in the following amended
claims.
* * * * *